Boat oar mechanism



Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to power transmitting lever systems or mechanisms adaptable for rowing operations.

This invention has utility when incorporated as row boat front-facing oar readily attachable, adjustable, and even convertible to a rear-facing oar.

Referring to the drawings:

Fig. 1 is a fragmentary plan view of a row boat equipped with an embodiment of the invention, shown at say approximately a limit position for the rower or oarsman to commence the pull on the oar for urging the boat forward in the direction the rower is facing;

Fig. 2 is a side elevation of the mechanism of Fig. l, at the oar stroke position in which the paddle of the oar is directly outward from the side of the boat or approximately perpendicular to the direction of boat transit;

Fig. 3 is a detail view, with parts broken away of the oar-lock or mounting for the device; and

Fig. 4 is an enlarged scale, partial side elevation of the mechanism of Fig. 2, in similar straight-out position, but as converted for the oarsman as pulling the oar handle toward his body, and facing toward the stern of the boat, thereby to urge the boat forward.

A row boat i is shown with a cross-seat 2 aft from its prow 3. Boat side or gunwale 4 near the seat 2 has rigidly mounted therewith a bracket device 5 with pivots 6 to provide a rockable mounting for a socket l. Fixed with the socket 'l is an inwardly extending arm 8 spaced from the bracket 5 by a tension spring 9. This arm 8 is approximately 45 downwardly inclined from oppositely extending oval cross section tubular arm I0 when such arm is horizontal in its normal slide-guide functioning position.

An oar-lock stem II is in the socket l and as extending upwardly out of the socket 'l has spread arms I'2 for horizontally extending axis or pivot pin I3 thru oar element I4, herein shown as a minor lever at its inner end having a hand grip portion I5. The lever I4 outer end has outwardly overhanging fork means at a pivot pin I6. The pivot pin i6 is embraced by an extension strap from a major length lever or element Il. The element I'I outer end is an oar blade or paddle I8 of straight or spoon type as may be desired.

The major lever I1 has a pivot pin or fulcrum I9. The lever I'4 has a xed fulcrum at the socket 'I in the pulling-of-the-oar for rowing direction of operation. To provide for ready knock-down handling, the pin I6 is removable.

The fulcrum I9 is a movable fulcrum projecting from and slidable with a guide block 20 directed by an oval cross section tubular floating third lever device in the mechanism. The third lever device 2l is an intermediate element in the oar mechanism. The lever 2| also has a movable fulcrum or pivot 22 in a guide block 23 movable along the tubular arm I0. These thin walled light metal tubular portions I0, 2l, as terminally sealed against water leakage thereinto establish for the mechanism sufliciently low specific gravity to maintain buoyancy or float characteristics in the event of any overboard mishap.

The intermediate oating control lever 2l has a terminal pivot connection 24 which at one adjustment may engage at mid point 25 oi the shorter arm or outward arm of the lever I4. Instead of this floating lever 2i connection with the lever I4 at the mid point 25, there is range for adjustment in the control transmission by locating the pivot pin 24 in a desired opening 26, 2l, for either shorter or longer arm from the socket l of the lever i4 in its action upon the lever 2| to shift the fulcrum I9 of the lever Il as modied by the guide arm Ill in controlling the fulcrum 22.

Due to the fact that the arm I9 carries the slide block 23 for the intermediate control lever 2I as the go-between for the lever sequences I4, Il, the oarsman, in the swinging of the paddle I8 clear of the water to bring such forward to start a working stroke for the oar, may depress the grip I5. This rocking is permitted by the pivotal mounting 6 for the socket and arm bracket means 1, 8, I0, and is yieldable due to the spring 9. The free or outward end of the arm I0 may swing up and down on the pivot 6. This freedom of movement. allows the oarsman to direct the proper elcient dip of the oar blade I8 into the water on the working or pull stroke.

Operating advantages in the mechanism are present, not only for the oarsman to see directly the boat direction, but efforts expended in rowing have transmission efficiency. For instance with the pull unity on the handle I5 parallel to the boat side 4 adjacent the seat 2 at the forward or start position of Fig. 1, upon test demonstrates that the pull transmitted is twenty-eight percent of such unity inward 4" from the tip of a 35 blade to the fulcrum I9. The at ellipse described by the fulcrum I9 in its orbit in the shift say from 30 away from the boatside to 45 upon pull test of unity demonstrates that here two tenths or twenty percent of such unity is transmitted perpendicular to the face of the blade I8 at 4" from its free end. For those two points were the oar one-piece straight, the transmissions would be eighteen instead of twenty-eight percent, and fourteen instead of twenty percent.

Should the oarsman deem it desirable to convert the mechanism herein to a rear-facing oar, such is achieved by using a hole 28 in the lever II, slightly away from the pivot IS, for a substitute pin 29 to engage the lever 2i as released from the arm I0, and thereby lock the element 2| with the lever Il at this second point in addition to the block 2U at the fulcrurn I9. Thus the connection of the element 2| at the pin 24 with the lever Id assembles the three lever elements I4, 2|, il, as a rigid unit. The released arm lil' may swing against a catch 30 as the inner shorter arm 8 is clear for the element I4 to be used as a rigid oar element in the oar-lock Ii, I2. An oarsman, sitting on the seat 2 and facing the prow 3, may grasp the oar portion I5. For a pull stroke o the mechanism, a drawing of the portion i5 is toward the seat 2 as the position of the oarsman changes from forward reach or incline to upright, or even leaning backward. The oar lever M is thus rocked on i-ts xed fulcrum The movement of the grip i5 backward causes the other or outer end or the lever lil, thru the pivot connection i6, to thrust the arm Il to swing on its ulcrum i9 for moving the paddle i8 in its outward rearward sweep. The extent of the clip of this rearward sweepI of the paddle I8 in the water is determined by the applied downward tilt to the arm i@ thru lifting of the grip l5. The mechanism in this operation has an intermediate lever control for shifting the fulcrum i9 of the paddle carrying lever Il, i8. This is thru a compound or iioating lever 2l having the pivotal connection 25 with the lever I4, the movable ulcrum block 23 on the arm Ill, and the slide block connection 2!) with the lever Il, i8. For the recover stroke, the oarsman depresses the grip- I5 to lift the paddle i8 clear of the water, and Ithen swings forward to the starting position in causing the grip I5 to move toward the prow 3 for a succeeding oar stroke.

What is claimed and it is desired to secure by Letters Patent is:

1. A power transmission mechanism comprising a support, a rst lever, a fulcrurn fixed on the support for the lever, there being a rockable connection directly between the fulcrum and lever, a second lever terminally connected with the rst lever, and a third control intermediate lever providing a fulcrum for the second lever movable relatively to the support and having connection with an arm of the rst lever spaced from the first lever fulcrum.

2. A boat oar lock having a guide arm adapted to extend outwardly from the side of a boat upon which the oar lock is mounted, a sectional oar comprising a first hand-grip providing lever having a fixed fulcrum in the oar lock, a second. paddle-providing lever terminally in series with the first lever, and a control intermediate lever having movable ulcrum mounting on the guide v arm and spaced therefrom, a fulcrum for the second lever movable relatively to the first lever fulcrum.

3. A multiple lever oar assembly including two levers in series, one xed .and two movable fulci'a, and, mounted by said fulcra, the said two levers in series and an intermediate lever, the latter lever extending between the two movable fulcra.

4. A front-facing boat oar mechanism including two levers having an inseries connection therebetween, mounting means providing two spaced apart fulcra, one for each of said two levers, and conversion means to back-facing oar assembly including holding means between the levers connecting one lever and its fulcrum, disconnectable mounting means for said holding means which when disconnected permits the holding means to move across the series connection between the two levers, and a lock cooperating between said holding means and the second lever to hold said two levers against articulation.

LAWRENCE A. CUMivllifTS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 419,898 Stewart Jan. 2, 1890 636,653 Foster Nov. 7, 1899 1,070,448 Gilbertson Aug. 19, 1913 

